Donald Bruce Stewart wrote:
> Perhas you'd like to put up a Style page on thew new Haskell wiki,
> perhaps under the Idioms category?
I cannot promise it, but I'll try. If someone else is willing to do it,
I would support this.
Rob Dockins wrote:
>> I understood that part of the guidelines as a pleading for Maybe.
>> Humm. Well clearly I read it the opposite way. I suppose that means that whatever technique is being recommended should be put forth with more clarity ;-)
done (use Maybe or another Monad)
Andrew Bromage wrote:
> So, for example, f (g (h x)) can be expressed well as:
>> f . g $ h x -- only use if you need to distinguish h
> f . g . h $ x -- better
I see this differently. Expressions may be succinct! I find "$" and "."
similar enough for non-obfuscation. But I collect cases where "$" does
not work (i.e. for the kind #). Bad would be cases where "$" works
differently than (reasonably) expected.
John Meacham wrote:
> f x = ... y ... where
> Just y = Map.lookup x theMap
>> now if the lookup fails you automatically get an error message pointing
> to the exact line number of the failure. or if the failure message of
> the routine is more important than the source location you can do
>> f x = ... y ... where
> Identity y = Map.lookup x theMap
These are potential runtime errors, that may be not so obvious to see in
the source (ie. for user defined types) and even the compiler (ghc) does
not emit a warning.
Thanks for all your comments
Christian